blob: e16aade51ae0462c2f0a7cdb72ec49346c56128e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Spanning tree protocol; BPDU handling
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14#include <linux/kernel.h>
15#include <linux/netfilter_bridge.h>
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -080016#include <linux/etherdevice.h>
17#include <linux/llc.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Eric W. Biedermane730c152007-09-17 11:53:39 -070019#include <net/net_namespace.h>
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080020#include <net/llc.h>
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -080021#include <net/llc_pdu.h>
Patrick McHardy7c85fbf2008-07-05 21:25:56 -070022#include <net/stp.h>
Peter Chubb4dc6d9c2006-03-23 21:39:47 -080023#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#include "br_private.h"
26#include "br_private_stp.h"
27
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080028#define STP_HZ 256
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080030#define LLC_RESERVE sizeof(struct llc_pdu_un)
31
32static void br_send_bpdu(struct net_bridge_port *p,
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090033 const unsigned char *data, int length)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034{
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080037 skb = dev_alloc_skb(length+LLC_RESERVE);
38 if (!skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080041 skb->dev = p->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 skb->protocol = htons(ETH_P_802_2);
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080043
44 skb_reserve(skb, LLC_RESERVE);
45 memcpy(__skb_put(skb, length), data, length);
46
47 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
48 LLC_SAP_BSPAN, LLC_PDU_CMD);
49 llc_pdu_init_as_ui_cmd(skb);
50
51 llc_mac_hdr_init(skb, p->dev->dev_addr, p->br->group_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Florian Westphale6f26122011-01-03 04:16:28 +000053 skb_reset_mac_header(skb);
54
Jan Engelhardt713aefa2010-03-23 04:07:21 +010055 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 dev_queue_xmit);
57}
58
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080059static inline void br_set_ticks(unsigned char *dest, int j)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080061 unsigned long ticks = (STP_HZ * j)/ HZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Harvey Harrisond3e2ce32008-05-02 16:26:16 -070063 put_unaligned_be16(ticks, dest);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064}
65
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080066static inline int br_get_ticks(const unsigned char *src)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Harvey Harrisond3e2ce32008-05-02 16:26:16 -070068 unsigned long ticks = get_unaligned_be16(src);
Stephen Hemminger18fdb2b2006-03-20 22:58:49 -080069
Ilpo Järvinen172589c2007-08-28 15:50:33 -070070 return DIV_ROUND_UP(ticks * HZ, STP_HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071}
72
73/* called under bridge lock */
74void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu)
75{
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080076 unsigned char buf[35];
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Stephen Hemminger9cde0702007-03-21 14:22:44 -070078 if (p->br->stp_enabled != BR_KERNEL_STP)
79 return;
80
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080081 buf[0] = 0;
82 buf[1] = 0;
83 buf[2] = 0;
84 buf[3] = BPDU_TYPE_CONFIG;
85 buf[4] = (bpdu->topology_change ? 0x01 : 0) |
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 (bpdu->topology_change_ack ? 0x80 : 0);
Stephen Hemminger12ac84c2006-03-20 22:59:49 -080087 buf[5] = bpdu->root.prio[0];
88 buf[6] = bpdu->root.prio[1];
89 buf[7] = bpdu->root.addr[0];
90 buf[8] = bpdu->root.addr[1];
91 buf[9] = bpdu->root.addr[2];
92 buf[10] = bpdu->root.addr[3];
93 buf[11] = bpdu->root.addr[4];
94 buf[12] = bpdu->root.addr[5];
95 buf[13] = (bpdu->root_path_cost >> 24) & 0xFF;
96 buf[14] = (bpdu->root_path_cost >> 16) & 0xFF;
97 buf[15] = (bpdu->root_path_cost >> 8) & 0xFF;
98 buf[16] = bpdu->root_path_cost & 0xFF;
99 buf[17] = bpdu->bridge_id.prio[0];
100 buf[18] = bpdu->bridge_id.prio[1];
101 buf[19] = bpdu->bridge_id.addr[0];
102 buf[20] = bpdu->bridge_id.addr[1];
103 buf[21] = bpdu->bridge_id.addr[2];
104 buf[22] = bpdu->bridge_id.addr[3];
105 buf[23] = bpdu->bridge_id.addr[4];
106 buf[24] = bpdu->bridge_id.addr[5];
107 buf[25] = (bpdu->port_id >> 8) & 0xFF;
108 buf[26] = bpdu->port_id & 0xFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800110 br_set_ticks(buf+27, bpdu->message_age);
111 br_set_ticks(buf+29, bpdu->max_age);
112 br_set_ticks(buf+31, bpdu->hello_time);
113 br_set_ticks(buf+33, bpdu->forward_delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800115 br_send_bpdu(p, buf, 35);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116}
117
118/* called under bridge lock */
119void br_send_tcn_bpdu(struct net_bridge_port *p)
120{
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800121 unsigned char buf[4];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700123 if (p->br->stp_enabled != BR_KERNEL_STP)
124 return;
125
Stephen Hemminger12ac84c2006-03-20 22:59:49 -0800126 buf[0] = 0;
127 buf[1] = 0;
128 buf[2] = 0;
129 buf[3] = BPDU_TYPE_TCN;
Stephen Hemminger485c2962006-09-13 20:12:40 -0700130 br_send_bpdu(p, buf, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800133/*
134 * Called from llc.
135 *
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000136 * NO locks, but rcu_read_lock
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800137 */
Patrick McHardy7c85fbf2008-07-05 21:25:56 -0700138void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
139 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140{
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800141 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a82010-06-15 06:50:45 +0000142 struct net_bridge_port *p;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800143 struct net_bridge *br;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800144 const unsigned char *buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800146 if (!pskb_may_pull(skb, 4))
147 goto err;
148
149 /* compare of protocol id and version */
150 buf = skb->data;
151 if (buf[0] != 0 || buf[1] != 0 || buf[2] != 0)
152 goto err;
153
stephen hemmingerb5ed54e2010-11-15 06:38:13 +0000154 p = br_port_get_rcu(dev);
155 if (!p)
156 goto err;
157
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800158 br = p->br;
159 spin_lock(&br->lock);
160
Stephen Hemminger9cde0702007-03-21 14:22:44 -0700161 if (br->stp_enabled != BR_KERNEL_STP)
162 goto out;
163
164 if (!(br->dev->flags & IFF_UP))
165 goto out;
166
167 if (p->state == BR_STATE_DISABLED)
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800168 goto out;
169
Stephen Hemmingerfda93d92006-03-20 22:59:21 -0800170 if (compare_ether_addr(dest, br->group_addr) != 0)
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800171 goto out;
Stephen Hemminger85967bb2005-05-29 14:15:55 -0700172
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800173 buf = skb_pull(skb, 3);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 if (buf[0] == BPDU_TYPE_CONFIG) {
176 struct br_config_bpdu bpdu;
177
178 if (!pskb_may_pull(skb, 32))
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800179 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
181 buf = skb->data;
182 bpdu.topology_change = (buf[1] & 0x01) ? 1 : 0;
183 bpdu.topology_change_ack = (buf[1] & 0x80) ? 1 : 0;
184
185 bpdu.root.prio[0] = buf[2];
186 bpdu.root.prio[1] = buf[3];
187 bpdu.root.addr[0] = buf[4];
188 bpdu.root.addr[1] = buf[5];
189 bpdu.root.addr[2] = buf[6];
190 bpdu.root.addr[3] = buf[7];
191 bpdu.root.addr[4] = buf[8];
192 bpdu.root.addr[5] = buf[9];
193 bpdu.root_path_cost =
194 (buf[10] << 24) |
195 (buf[11] << 16) |
196 (buf[12] << 8) |
197 buf[13];
198 bpdu.bridge_id.prio[0] = buf[14];
199 bpdu.bridge_id.prio[1] = buf[15];
200 bpdu.bridge_id.addr[0] = buf[16];
201 bpdu.bridge_id.addr[1] = buf[17];
202 bpdu.bridge_id.addr[2] = buf[18];
203 bpdu.bridge_id.addr[3] = buf[19];
204 bpdu.bridge_id.addr[4] = buf[20];
205 bpdu.bridge_id.addr[5] = buf[21];
206 bpdu.port_id = (buf[22] << 8) | buf[23];
207
208 bpdu.message_age = br_get_ticks(buf+24);
209 bpdu.max_age = br_get_ticks(buf+26);
210 bpdu.hello_time = br_get_ticks(buf+28);
211 bpdu.forward_delay = br_get_ticks(buf+30);
212
stephen hemminger0652cac2011-07-22 07:47:07 +0000213 if (bpdu.message_age > bpdu.max_age) {
214 if (net_ratelimit())
215 br_notice(p->br,
216 "port %u config from %pM"
217 " (message_age %ul > max_age %ul)\n",
218 p->port_no,
219 eth_hdr(skb)->h_source,
220 bpdu.message_age, bpdu.max_age);
221 goto out;
222 }
223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 br_received_config_bpdu(p, &bpdu);
stephen hemminger160d73b2011-07-22 07:47:10 +0000225 } else if (buf[0] == BPDU_TYPE_TCN) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 br_received_tcn_bpdu(p);
227 }
228 out:
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800229 spin_unlock(&br->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 err:
231 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}